I am in New Plymouth and have built a number of battery packs for ebikes and have built my own for my foil. Have a reliable supplier for 18650 cells but it is the freight that is really high as they are dangerous goods. Have not worried about a bms on thefoil as they can be unreliable but have seen a new model come up that looks promising and will use on next battery build. It can also be programmed by your phone.
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Do you have surplus cells or are you looking at getting some more in soon? Would be interested in splitting shipping costs etc. What cells are you using?
I wasn’t going to use a BMS either, as I was planning to build 2x 6S packs to allow charging on a balance charger and then I monitor each cell with my arduino and stop is any issues with a cell. That BMS looks pretty sweet but it is huge!
For my ebike batteries I have always used a bms but my foil has 2x6s and use a balance charger like you are thinking of using. The cell I use are ncr18650pf Panasonic. Am looking at getting some soon will let you know when I do.
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I was just looking at Hobbyking Multistar batteries. What happened to their pricing? I bought 4s 10Ah batteries for $25 two years ago. They now have the same batteries for $90 on sale at half price. That makes its super expensive to go with batteries that are going to have issues with charging and such. Better to go cylindrical cells or buy ebike batteries.
Our board has a 36v 40Ah pack. To get a similar size pack from Hobbyking would be 8*$90 or $720. Much better idea to get some longer lasting batteries.
Hello, I am new to this forum and have started building my efoil. I am looking into batteries and was wondering if these batteries from AliExpress are a good option:
Interesting find! Unfortunately, I do not know enough about battery packs to help you out, but I would like to know as well!
@gtoledo, nice find !
It looks very appropriate for what we want to do.
Capacity of 35Ahr at 48V should give a flight time of about 1 hour assuming flight at 1.5kW.
100A continuous discharge at 48V gives ~4.8kW which is enough for liftoff and ofcourse for flight.
Only down side I see in the specs is the charge at 5A which will take 7 hours for a full charge.
The biggest concern is will they meet the specs… but on paper it looks approproate.
But for this price including a charger its a great catch in my mind.
Looking up I see 3d printed cell holders. Bad idea.
It melts during a fault. Then bad things touch. Goes critical. It absolutely happens.
Don’t put thermo plastics near batteries. Only use silicone or high temp wire fir same.
It shouldn’t matter, the holders are only for support. The Nickel strip would hold the cells in place.
You are right that this would prevent a short if the cell holders melt. I would however not suggest to use the nickel strips as main fastening method for the cells. This is not an immediate issue, but with time and vibration a loaded spot weld could fail.
If you are still looking for shock-proof IP67 battery pack made in germany not china…
-Samsung Cells inside
- IP67 waterproof
-smart battery management system
Monitor cell, PCB temperature
Control charge and discharge current
Automatic disconnect at under- or overvoltage
Cell-balancing
-50V inteli-safe-connection
-up to 120A cont. discharge
-max Charge rate 8A
-CAN-Bus, UART, I²C
-USB-Interface for service
-SOC (state of charge) display
-lifetime up to 2000cycles
-Endurance 1 hour with elevate prop unit
215x310x75mm weight 6kg
should be usable for most of your DIY builds 
available spring 2019
Elevate Intelli IP67 battery
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I was wondering if you ended up buying a Tesla battery, and if so how hard was it to salvage the cells.
@ELEVATE.rocks
Seems great! any specs you might want to share? like price, current discharge rates, charge current, cell configuration …
values have been updated above 
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Did not buy, would not recomend it. Very hard to salvage individual cells and dangorus.
Thanks. It looks like it would be nearly impossible to remove them with out shorting something out. Too bad you can’t full discharge them first.
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What the proposed cost?
I have had problems using nickel strips as the + and - discharge areas get really hot with the amount of amps running through them and melt heatshrink around battery causing a short. You need to either double up nickel strips or solder some awg 12 wire across the terminals to help even out the load and keep temp down.
Hello fellow buiders,
due to lack of time I decided to end my project for now and sell my battery 92V 35AH with charger, ESC FLIER with ubec and SSS motor 56114 360KV, if anybody is interested.
Everything is new, I bought new Panasonic batteries on NKON page last summer(Panasonic NCR18650PF 2900mAh - 10A - 18650 - Li-ion - Rechargeable batteries | NKON )
Battery is 22S12P, I made battery on my own, check voltage of every single cell, using battery spacers, glued all cells together with hot glue, put in a foam and thermoelastic bag. Battery has 100 Amps continious discharge BMS (see pictures), 8 AWG wires with power anderson conector, anti-spark wire, connection for UBEC, and wire for charging.
I welded batteries with Sunkko welding machine, using pure nickel strips, so I didnt overheat the cells. I charged the battery with 7Amps; 92,4V charger for test only once.
I tried to use direct drive APS 56115 motor, but I didnt succeed, because of not enough torque. So the 3 Volt drop, you see on the picture is from testing, this is it.
Motor SS 56114, 360 KV is new, I just tested RPM last weak (on 89,4V battery) with tachometer and measure 36590, so the motor is actually 400 KV.
ESC is BOAT FLIER 400A, 4-22S with usb for computer connection, instruction and UBEC.
I can sell battery individualy with charger or everything together with motor and ESC.
Prices: Panasonic batteries cost me 560E
BMS 100A 50E
Charger 120E
Other material for battery 30 E
all together battery with cahrger is 750E
motor SSS power 360 kv is 150 E
ESC with ubec is 250E
all together 1150 E. For extra I can add water pump never used and some connectors I didnt use.
I will not negotiate for a price a lot ;), because I think is more than fair.
You need to buy Reisenauer planetary gearbox 6:1, because of a lot of rpms.
Plese fell free to ask and contact me if you are interested.
Nace from Slovenia, EUROPE
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What is that white padding material in the last photo called?